The present invention relates to vehicle washing apparatus, and particularly to automatic vehicle washing apparatus.
Automatic vehicle washing systems are designed to wash automobiles or other vehicles without manual labor. The washing is most generally accomplished by brushes or clothes contacting the surface of the vehicle, or by high pressure jets of water and detergent.
One problem that is encountered in automatic car washes is the cost of the equipment used to do the washing automatically. In the case of brushes and clothes, another problem is that the brushes and clothes get dirty in the washing process and, unless cleaned between uses, scratch the surface of vehicles being washed with the dirt embedded in the brushes or clothes. In the case of high pressure jets, much of the fluid dispensed by the jets is often wasted due to inefficient positioning and excessive distance between the nozzle and the vehicle.
One idea suggested to improve automatic car washes is to have the washing device follow the contour of the vehicle as it passes over the vehicle. Examples of proposed devices using photodetector contour sensing car washing equipment are disclosed in U.S. Pat. Nos. 3,410,284 to Burger and 3,533,422 to Alimanestiano.
In the Alimanestiano device, the washing assembly is supported from the top and moves over the stationary car. Photoelectric emitters and detectors are arranged to transmit and receive four horizontal, parallel beams of light. When the vehicle being washed obscures certain of the beams, a control device cause the vehicle washing device to be raised and stops the horizontal movement of the assembly.
The Burger patent discloses several arrangements of horizontal beams for detecting the contour of a vehicle being washed and control means to raise and lower an overhead supported washing assembly. The Burger patent discloses that when a wash assembly is wide in the horizontal direction of relative movement between the assembly and the vehicle, it is advantageous to provide electric eyes on both sides of the washing device. The result is the equivalent of the four parallel beams of the Alimanestiano device.
Even these proposed contour-following devices have many inadequacies. Primarily they are mechanically complicated, resulting in a large initial expense plus a significant possibility of malfunctioning, with no method of preventing damage to a vehicle in the event of a malfunction. Additionally, the proposed devices, if used in a facility in which vehicles on a conveyor pass a stationary contour-following device, have no way of compensating for the horizontal distance vehicles move while the device makes vertical adjustments, especially where the vehicles move past the device at varying speeds depending on the desires of the facility operator. Also, the proposed devices are quite inadequate in view of the variety of vehicle shapes and sizes in use today, especially when combined with variable conveyor speeds.